melting point determinations 
 were performed by the open capillary method and are reported uncorrected .
h and c nmr chemical shifts (  ) are reported 
 in parts per million ( ppm ) relative to tms , and coupling constants j are reported to the nearest 0.1 hz .
c , ch , ch2 , or ch3c signals are assigned from dept-90 
 and 135 spectra . in a number of cases ,
carbon atoms attached to boron 
 gave very broad peaks in c nmr spectra , and these could 
 not always be distinguished .
hydrogen atoms attached to these carbons 
 were not always observed in h nmr spectra .
low- and high - resolution 
 mass spectra were recorded on a time - of - fight mass spectrometer using 
 electron impact ( ei ) .
ir spectra were recorded on a ft - ir spectrometer 
 as a thin film ( liquid samples ) or applied as a solution in chloroform , 
 and the chloroform was allowed to evaporate ( solid samples ) .
gc determinations were performed using a gas chromatograph fitted 
 with a zb-5 column ( 30 m , 0.32 mm inner diameter , 1.0 m film 
 thickness ) .
the carrier gas was he at 69.3 kpa , and a split injection 
 mode was used .
the oven temperature was increased from 70 to 260 c 
 at 6 c min and then held for 4 min .
authentic 
 samples of products were used to determine response factors relative 
 to tetradecane , a known amount of which was added to reaction mixtures 
 to allow quantification of product yields .
a mixture of propiolic 
 acid ( 8.79 ml , 
 0.143 mol ) and aq hbr ( 48% , 40 ml ) was heated at 95 c for 2.5 
 h , then left to cool .
the crude product was filtered , washed with 
 cold water ( 3  25 ml ) , and dried in air to give ( e)-3-bromoacrylic acid as colorless needles ( 13.49 g , 63% ) ; 
 mp 120121.5 c ( lit .
a 
 two - necked round - bottomed flask equipped 
 with a magnetic stirrer bar , septum , and septum - capped dropping funnel 
 was assembled hot and flushed with n2 .
( e)-3-bromoacrylic acid ( 8.00 g , 53 mmol ) was dissolved in dry diethyl 
 ether ( 40 ml ) and transferred via syringe to the dropping funnel . 

powdered lialh4 ( 4.02 g , 106 mmol ) was transferred quickly 
 to the reaction flask , and dry diethyl ether ( 40 ml ) was added .
the 
 reaction mixture was cooled in an ice bath , and the solution of 3-bromoacrylic 
 acid was added dropwise via the dropping funnel with vigorous stirring . 

the mixture was stirred for 2 h , then water ( 2.5 ml ) was added dropwise , 
 followed by 15% naoh ( 5.25 ml ) and more water ( 7.4 ml ) .
the resulting 
 salts were washed with diethyl ether ( 3  50 ml ) , and the combined 
 extracts were dried over sodium sulfate and concentrated under reduced 
 pressure to give fairly pure ( e)-3-bromoprop-2-en-1-ol 
 as a yellow liquid ( 4.16 g , 57% ) . a 50 ml round - bottomed flask equipped 
 with a magnetic stirrer bar was charged with ( e)-3-bromoprop-2-en-1-ol 
 ( 3.52 g , 25.7 mmol ) and cooled using an ice bath .
hexachloroacetone 
 ( 7.79 ml , 51.4 mmol ) was added and the solution stirred for 5 min . 

powdered triphenylphosphine ( 6.74 g , 25.7 mmol ) was added portionwise 
 over a period of 25 min .
the mixture was stirred for 2 h at 0 c , 
 then fractionally distilled under reduced pressure to give 90% pure 
 ( e)-1-bromo-3-chloroprop-1-ene , which was fractionally 
 distilled a second time to give pure ( e)-1-bromo-3-chloroprop-1-ene 
 ( 5 ) as a colorless liquid ( 0.52 g , 13% ) : h ( 500 mhz , cdcl3 )  6.48 ( 1h , dt , j = 13.5 , 1.1 hz ) , 6.34 ( 1h , dt , j = 13.5 , 7.1 hz ) , 
 4.02 ( 2h , dd , j = 7.1 , 1.1 hz ) ; c ( 125 
 mhz , cdcl3 )  133.1 ( ch ) , 110.8 ( ch ) , 43.6 ( ch2 ) .
boronate 
 esters 3 where r = bn and 4-meobn were purchased from 
 sigma - aldrich 
 and tci , respectively , and used without further purification .
boronate 
 esters 3 where r = bu , i - pr , and cyclohexyl 
 were prepared from the reaction of their corresponding boronic acids 
 with pinacol in pentane in 73 , 36 , and 32% yields , respectively .
boronate 
 ester 3 where r = tert - bu was prepared 
 by the literature method from pinacolborane and tert - bumgcl in 40% yield .
boronate ester 3 where r = thexyl was prepared by the method previously described 
 from the monohydroboration of 2,3-dimethyl-2-butene and subsequent 
 reaction with pinacol , while boronate esters 11 and 12 were also prepared as described previously .
the procedure 
 for preparation of 13 ( r = c - hex , r = phch = ch ) is typical .
characterization 
 details of the other boronate esters 13 can be found 
 in our previous publication .
dicyclohexylborane 
 was prepared by the dropwise addition of cyclohexene ( 2.12 ml , 20.9 
 mmol ) to borane dimethyl sulfide complex ( 10 m , 1.00 ml , 10.0 mmol ) . 

the mixture was stirred at room temperature for 2 h , dry thf ( 10 ml ) 
 was added , then the mixture was kept at 0 c during the dropwise 
 addition of phenylacetylene ( 1.15 ml , 10.5 mmol ) .
the mixture 
 was stirred for 1 h at 0 c and 1 h at room temperature then 
 recooled to 0 c .
dichloromethyl methyl ether ( 1.36 ml , 15.0 
 mmol ) was added dropwise , followed by a freshly prepared solution 
 of lithium triethylcarboxide ( dropwise addition of n - buli ( 1.6 m in hexanes , 9.38 ml , 15.0 mmol ) to a solution of 3-ethyl-3-pentanol 
 ( 2.12 ml , 15.0 mmol ) in thf ( 10 ml ) ) dropwise via a cannula over a 
 20 min period .
the ice bath was removed and the mixture left to stir 
 for a further 1 h. 2,2-dimethyl-1,3-propanediol ( 1.57 g , 15.0 
 mmol ) in dry thf ( 5 ml ) was added and the reaction mixture left to 
 stir overnight at room temperature .
the crude product following workup 
 was separated by column chromatography on silica ( petroleum ether ) 
 to give pure ( e)-2-(1,1-dicyclohexyl-3-phenylallyl)-5,5-dimethyl-1,3,2-dioxaborinane 
 ( 1.19 g , 20% ) as cubic crystals : mp 188189 c ; h ( 400 mhz , cdcl3 )  7.40 ( 2h , d , j = 7.2 hz ) , 7.29 ( 2h , app t , j = 7.6 hz ) , 7.16 ( 1h , 
 t , j = 7.3 hz ) , 6.36 ( 1h , d , j = 
 16.7 hz ) , 6.25 ( 1h , d , j = 16.7 hz ) , 3.65 ( 4h , s ) , 
 0.911.82 ( 22h , m ) , 1.01 ( 6h , s ) ; c ( 125 mhz , 
 cdcl3 ) ( quat c next to boron not seen ) 
  139.4 ( quat c ) , 135.9 ( ch ) , 129.0 ( ch ) , 128.4 ( ch ) , 126.2 
 ( ch ) , 126.1 ( ch ) , 71.9 ( ch2 ) , 41.1 ( ch ) , 31.4 ( quat c ) , 
 30.5 ( ch2 ) , 29.2 ( ch2 ) , 27.7 ( ch2 ) , 27.4 ( ch2 ) , 27.3 ( ch2 ) , 22.6 ( ch3 ) ; b{h } ( 96.2 mhz , cdcl3 )  
 29.3 ; hr - ei ms m / z ( % ) 
 calcd for c26h39bo2 394.3043 , 
 found 394.3049 ( m , 39% ) . a mixture of the appropriate 
 boronic ester 3 , 11 , 12 , or 13 ( 1 equiv ) , 1-bromo-3-chloroprop-1-ene ( 5 , 
 1.1 equiv ) , and dry thf in a dry 50 ml round - bottomed flask equipped 
 with a magnetic stirrer bar and septum was cooled to 78 c , 
 and t - buli in hexanes ( 1.1 equiv ) was added dropwise 
 with vigorous stirring , and the mixture was stirred for an additional 
 30 min .
the cooling bath was removed and the reaction mixture left 
 to warm to 20 c over 3 h. an accurately weighed amount of tetradecane 
 ( 0.2 ml ) was added as a standard to enable gc determination 
 of the amount of desired product formed following workup .
the reaction 
 mixture was cooled to 0 c , then oxidized by dropwise addition 
 of excess naoh ( 0.6 g in 5 ml of h2o ) , followed by hydrogen 
 peroxide ( 30% by weight , 3 ml ) .
once the initial exothermic reaction 
 subsided , the cooling bath was removed and the mixture left to stir 
 overnight at room temperature .
diethyl ether ( 10 ml ) was added , the 
 aqueous layer saturated with sodium chloride , and a small aliquot 
 taken from the organic phase for gc analysis .
the extract was washed with water 
 ( 10 ml ) and brine ( 10 ml ) , then dried over mgso4 to give 
 a crude product containing the desired 3-alkylprop-1-en-3-ol 9 or 14 , which was estimated by gc . in some cases 

( see below ) , mixtures were separated by column chromatography on silica 
 ( prewashed with 3% triethylamine in petroleum ether , petroleum ether / ethyl 
 acetate 95:5 through 85:15 ) to provide the pure products . from 3 ( r = thexyl )
( 0.564 g , 
 2.66 mmol ) , 5 ( 0.416 g , 2.68 mmol ) , thf ( 15 ml ) , and t - buli in hexanes ( 1.9 m , 1.41 ml , 2.68 mmol ) ( note that 
 the excess of 5 and organolithium reagent was smaller 
 in this example ) ; colorless oil ( 0.105 g , 28% ) ; h ( 400 
 mhz , cdcl3 )  5.94 ( 1h , ddd , j = 
 17.2 , 10.5 , 6.7 hz ) , 5.23 ( 1h , d , j = 17.2 hz ) , 5.18 
 ( 1h , d , j = 10.5 hz ) , 4.01 ( 1h , d , j = 6.7 hz , choh ) , 1.73 ( 1h , app sept , j = 7.0 hz ) , 1.47 ( 1h , br s ) , 0.87 ( 3h , d , j = 6.9 
 hz ) , 0.850.82 ( 6h , m ) , 0.73 ( 3h , s ) ; c ( 125 mhz , 
 cdcl3 )  138.5 ( ch ) , 116.5 ( ch2 ) , 78.1 
 ( ch ) , 39.6 ( quat c ) , 32.9 ( ch ) , 19.0 ( ch3 ) , 18.6 ( ch3 ) , 17.5 ( ch3 ) , 17.4 ( ch3 ) ; hrms ( ei ) m / z calcd for c9h18o 124.1252 , found 124.1252 ( m  

h2o ) . from 13 ( r = r = et ) ( 0.335 g , 1.58 mmol ) , 5 ( 0.274 
 g , 1.76 mmol ) , dry thf ( 10 ml ) , and t - buli in hexanes 
 ( 1.6 m , 1.09 ml , 1.74 mmol ) ; colorless liquid ( 0.042 g , 17% ) ; h ( 500 mhz , cdcl3 )  6.02 ( 1h , ddd , j = 17.2 , 10.5 , 6.6 hz ) , 5.24 ( 1h , app dt , j = 17.2 , 1.6 hz ) , 5.16 ( 1h , app dt , j = 10.5 , 1.6 
 hz ) , 4.003.96 ( 1h , m ) , 1.411.28 ( 6h , m ) , 0.84 ( 9h , 
 t , j = 7.6 hz ) ; c ( 125 mhz , cdcl3 )  138.8 ( ch ) , 115.9 ( ch ) , 78.4 ( ch ) , 41.7 ( quat c ) , 
 26.0 ( ch2 ) , 8.5 ( ch3 ) ; hrms ( ei ) m / z calcd for c10h20o 156.1514 , found 156.1509 ( m ) . from 3 ( r = bn ) ( 0.280 
 g , 1.28 mmol ) , 5 ( 0.226 g , 1.45 mmol ) , dry thf ( 10 ml ) , 
 and t - buli in hexanes ( 1.5 m , 0.97 ml , 1.46 mmol ) ; 
 colorless oil ( 0.097 g , 52% ) ; h ( 400 mhz , cdcl3 )  7.24 ( 2h , app t , j = 6.9 hz ) , 7.197.15 
 ( 3h , m ) , 5.86 ( 1h , ddd , j = 17.2 , 10.5 , 5.8 hz ) , 
 5.18 ( 1h , app dt , j = 17.2 , 1.4 hz ) , 5.06 ( 1h , app 
 dt , j = 10.5 , 1.3 hz ) , 4.314.24 ( 1h , m ) , 
 2.82 ( 1h , dd , j = 13.6 , 5.1 hz ) , 2.72 ( 1h , dd , j = 13.6 , 8.0 hz ) , 1.64 ( 1h , br s ) ; c ( 125 
 mhz , cdcl3 )  140.2 ( ch ) , 137.8 ( quat c ) , 129.7 ( ch ) , 
 128.6 ( ch ) , 126.7 ( ch ) , 115.1 ( ch2 ) , 73.8 ( ch ) , 43.9 ( ch2 ) ; lrms ( ei ) m / z 148 ( m , 4% ) . from 
 4-methoxybenzylboronic acid pinacol ester ( 0.292 g , 1.18 
 mmol ) , 5 ( 0.210 g , 1.35 mmol ) , dry thf ( 10 ml ) , and t - buli in hexanes ( 1.5 m , 0.84 ml , 1.26 mmol ) ; colorless 
 oil ( 0.185 g , 52% ) ; h ( 400 mhz , cdcl3 )  
 7.15 ( 2h , d , j = 8.7 hz ) , 6.86 ( 2h , d , j = 8.7 hz ) , 5.93 ( 1h , ddd , j = 17.2 , 10.5 , 5.8 hz ) , 
 5.24 ( 1h , app dt , j = 17.2 , 1.4 hz ) , 5.13 ( 1h , app 
 dt , j = 10.5 , 1.4 hz ) , 4.344.27 ( 1h , m ) , 
 3.79 ( 3h , s ) , 2.83 ( 1h , dd , j = 13.7 , 5.1 hz ) , 2.73 
 ( 1h , dd , j = 13.7 , 7.9 hz ) , 1.65 ( 1h , br s ) ; c ( 125 mhz , cdcl3 )  158.4 ( quat c ) , 140.3 
 ( ch ) , 130.5 ( ch ) , 129.7 ( quat c ) , 114.8 ( ch2 ) , 114.0 ( ch ) , 
 73.7 ( ch ) , 55.3 ( ch3 ) , 42.9 ( ch2 ) ; lrms ( ei ) m / z 178 ( m , 45% ) . an oven - dried 50 ml round - bottomed 
 flask equipped with a magnetic stirrer bar and septum was flushed 
 with n2 .
vinylmagnesium bromide solution in thf ( 0.7 
 m , 1.2 equiv ) was added , and the mixture was cooled to 0 c . 

the appropriate aldehyde ( 1 equiv ) was added dropwise , and the mixture 
 was stirred for 15 min .
distilled water ( 10 ml ) was added and the 
 product extracted with diethyl ether ( 3  20 ml ) .
the combined 
 organic extracts were washed with water ( 2  10 ml ) , dried over 
 magnesium sulfate , filtered , and concentrated under reduced pressure 
 to give the product . from vinylmgbr 
 ( 0.7 m , 20 ml , 14 mmol ) 
 and valeraldehyde ( 1.24 ml , 11.7 mmol ) ; light yellow liquid ( 0.73 
 g , 55% ) ; h ( 400 mhz , cdcl3 )  5.86 ( 1h , 
 ddd , j = 17.2 , 10.5 , 6.3 hz ) , 5.21 ( 1h , app dt , j = 17.2 , 1.4 hz ) , 5.09 ( 1h , app dt , j = 
 10.5 , 1.4 hz ) , 4.08 ( 1h , app q , j = 6.7 hz ) , 1.77 
 ( 1h , br s ) , 1.601.44 ( 2h , m ) , 1.411.23 ( 4h , m ) , 0.89 
 ( 3h , app t , j = 7.2 hz ) ; c ( 125 mhz , 
 cdcl3 )  141.5 ( ch ) , 114.6 ( ch2 ) , 73.4 
 ( ch ) , 36.9 ( ch2 ) , 27.6 ( ch2 ) , 22.8 ( ch2 ) , 14.1 ( ch3 ) . from 
 vinylmgbr ( 0.7 m , 
 30 ml , 21 mmol ) and isobutyraldehyde ( 1.60 ml , 17.5 mmol ) ; 
 colorless liquid ( 1.49 g , 85% ) ; h ( 500 mhz , cdcl3 )  5.86 ( 1h , ddd , j = 17.2 , 10.5 , 6.4 hz ) , 
 5.22 ( 1h , app dt , j = 17.2 , 1.5 hz ) , 5.15 ( 1h , app 
 dt , j = 10.5 , 1.5 hz ) , 3.86 ( 1h , app t , j = 6.1 hz ) , 1.781.67 ( 1h , m ) , 1.58 ( 1h , br s ) , 0.93 ( 3h , 
 d , j = 6.8 hz ) , 0.90 ( 3h , d , j = 
 6.8 hz ) ; c ( 125 mhz , cdcl3 )  139.7 
 ( ch ) , 115.7 ( ch2 ) , 78.4 ( ch ) , 33.8 ( ch ) , 18.3 ( ch3 ) , 17.9 ( ch3 ) . from vinylmgbr 
 ( 0.7 m , 10 ml , 7 mmol ) and cyclohexanecarboxaldehyde ( 0.71 
 ml , 5.9 mmol ) ; colorless liquid ( 0.50 g , 61% ) ; h ( 500 
 mhz , cdcl3 )  5.86 ( 1h , ddd , j = 
 17.2 , 10.4 , 6.6 hz ) , 5.20 ( 1h , app dt , j = 17.2 , 
 1.6 hz ) , 5.14 ( 1h , app dt , j = 10.4 , 1.6 hz ) , 3.84 
 ( 1h , app t , j = 6.4 hz ) , 1.881.81 ( 1h , m ) , 
 1.791.70 ( 2h , m ) , 1.701.62 ( 2h , m ) , 1.55 ( 1h , br s ) , 
 1.440.93 ( 6h , m ) ; c ( 125 mhz , cdcl3 )  140.0 ( ch ) , 115.6 ( ch2 ) , 77.9 ( ch ) , 43.7 ( ch ) , 
 28.9 ( ch2 ) , 28.5 ( ch2 ) , 26.7 ( ch2 ) , 26.3 ( ch2 ) , 26.2 ( ch2 ) .
borane dimethyl sulfide ( 10 m , 1.94 ml , 
 19.4 mmol ) was added to a 50 ml round - bottomed flask equipped with 
 a stirrer bar and under n2 .
the flask was cooled in an 
 ice bath , and a solution of pinacol ( 2.29 g 19.4 mmol ) in dry dichloromethane 
 ( 10 ml ) was added dropwise over a period of 10 min .
the reaction mixture 
 was stirred for an hour at 0 c and a further hour at room temperature 
 before being transferred dropwise via cannula to a 100 ml round - bottomed 
 flask equipped with a stirrer bar and a suspension of wilkinson s 
 catalyst ( 0.16 g , 0.17 mmol , 1 mol % ) in dry dichloromethane ( 5 ml ) . 

the reaction mixture was stirred for 5 min , then tert - butyl but-3-enoate ( 2.50 g , 17.6 mmol ) was added dropwise over a 
 period of 10 min .
hexane ( 20 ml ) was added , 
 the mixture was filtered , and the filtrate was concentrated to give 
 the crude product ( 4.30 g , 91% ) , which consisted of boronic esters 15 and 16 ( 85:15 by relative integrations by h nmr ) .
this was separated by column chromatography on silica 
 ( 98:2 petroleum ether / ethyl acetate , followed by 95:5 , 90:10 , and 
 finally 85:15 ) to give boronate ester 15 as a colorless 
 oil ( 1.80 g , 50% ) : h ( 400 mhz , cdcl3 )  
 2.21 ( 2h , t , j = 7.6 hz ) , 1.69 ( 2h , app pent , j = 7.7 hz ) , 1.43 ( 9h , s ) , 1.23 ( 12h , s ) , 0.79 ( 2h , t , j = 7.8 hz ) ; c ( 125 mhz , cdcl3 ) 
  173.1 ( quat c ) , 83.1 ( quat c ) , 80.0 ( quat c ) , 38.0 ( ch2 ) , 28.3 ( ch3 ) , 24.9 ( ch3 ) , 19.9 ( ch2 ) , 10.7 ( br , ch2b ) ; b{h } ( 96.2 mhz , cdcl3 )  32.8 ; hr - ei ms m / z ( % ) calcd for c10h18bo3 197.1349 , found 197.1353 ( m  oc(ch3)3 , 41% ) .
tert - butyl-5-hydroxyhept-6-enoate 
 ( 17 , 96% yield by gc ) was prepared under the standard 
 conditions ( see section on reactions of alkylboronic esters with 5 and tert - buli ; general procedure ) from 
 boronate ester 15 ( 0.631 g , 2.34 mmol ) , 5 ( 0.423 g , 2.72 mmol ) , dry thf ( 10 ml ) , and t - buli 
 in hexanes ( 1.5 m , 1.81 ml , 2.72 mmol ) , except that after oxidation 
 of the organoboron compound with alkaline hydrogen peroxide the mixture 
 was made acidic ( ph 3 ) by addition of hcl , prior to saturation 
 with sodium chloride and extraction .
the crude product was separated 
 by column chromatography on silica gel ( 90:10 petroleum ether / ethyl 
 acetate , followed by 85:15 ) to give 17 as a colorless 
 oil ( 0.183 g , 39% ) : h ( 400 mhz , cdcl3 )  
 5.84 ( 1h , ddd , j = 17.2 , 10.4 , 6.2 hz ) , 5.21 ( 1h , 
 dt , j = 17.2 , 1.4 hz ) , 5.09 ( 1h , dt , j = 10.4 , 1.4 hz ) , 4.09 ( 1h , app q , j = 6.6 hz ) , 
 2.24 ( 2h , app t , j = 7.5 hz ) , 2.01 ( 1h , br ) , 1.721.57 
 ( 2h , m ) , 1.591.48 ( 2h , m ) , 1.42 ( 12h , s ) ; c ( 125 
 mhz , cdcl3 )  173.1 ( quat c ) , 140.9 ( ch ) , 114.8 ( ch2 ) , 80.3 ( quat c ) , 72.7 ( ch ) , 36.3 ( ch2 ) , 35.2 ( ch2 ) , 28.1 ( ch3 ) , 20.8 ( ch2 ) ; hr - ei ms m / z ( % ) calcd for c7h11o2 127.0759 , found 127.0759 ( m
tert - butyl 5-hydroxyhept-6-enoate ( 17 , 0.069 g , 0.345 
 mmol ) , dry benzene ( 10 ml ) , and p - toluenesulfonic 
 acid monohydrate ( 0.018 g , 0.093 mmol ) were 
 added to a 25 ml round - bottomed flask equipped with a stirrer bar 
 and a condenser .
the reaction mixture was heated to reflux ( bath temperature 
 = 100 c ) for 4 h. the reaction mixture was concentrated under 
 reduced pressure , hexane ( 20 ml ) was added , and the mixture was filtered . 

the filtrate was concentrated under reduced pressure to give lactone 18 as a light yellow oil ( 0.044 g , 100% ) : h ( 500 
 mhz , cdcl3 )  5.86 ( 1h , ddd , j = 
 17.2 , 10.6 , 5.5 hz ) , 5.34 ( 1h , dt , j = 17.2 , 1.4 
 hz ) , 5.23 ( 1h , dt , j = 10.6 , 1.4 hz ) , 4.844.79 
 ( 1h , m ) , 2.622.55 ( 1h , m ) , 2.522.44 ( 1h , m ) , 2.021.81 
 ( 3h , m ) , 1.701.61 ( 1h , m ) ; c ( 125 mhz , cdcl3 )  171.2 ( quat c ) , 136.1 ( ch ) , 117.0 ( ch2 ) , 80.4 ( ch ) , 29.7 ( ch2 ) , 28.0 ( ch2 ) , 18.2 
 ( ch2 ) ; hr - ei ms m / z ( % ) calcd for c7h10o2 126.0681 , found 126.0678 ( m , 20% ) .
 the reagent 3-chloro-1-lithiopropene 
 ( 4 ) can 
 be generated by treating 1-bromo-3-chloropropene with t - buli . 
 it is unstable but if generated at low temperature 
 in the presence of alkylboronic esters , such as 3 , is 
 trapped in situ to give rearrangement products 2 , which 
 on oxidation give 3-alkylprop-1-en-3-ols in good yields . 
 the reaction 
 works for primary , secondary , benzylic , and even tertiary alkylboronic 
 esters , providing allylic alcohols bearing almost any alkyl group 
 available using organoborane chemistry and incorporating all features 
 of such groups . 