Patent ID: 7901904

Claim:
A method for preparing compounds of formula (I): wherein X is a member of the group consisting of O and wherein R a is H, lower alkyl, alkenyl or alkynyl; and R is: (a) halogen; (b) OR b , wherein R b is H, lower alkyl or aryl; (c) C1-C6 cycloalkyl, optionally substituted with 1-3 substituents selected from the group consisting of halogen, lower alkyl, aryl, and OR b wherein Rb is H, lower alkyl, and aryl; (d) C6-C10 heteroaryl, optionally substituted with 1-3 substituents selected from the group consisting of halogen, lower alkyl, aryl, and OR b wherein Rb is H, lower alkyl, or aryl; or (e) C6-C10 aryl optionally substituted with 1-3 substituents selected from the group consisting of (a) halogen; (b) OR b , wherein R b is H, lower alkyl, or aryl; (c) C1-C6 linear, branched or cyclic alkyl, optionally substituted with 1-3 substituents selected from the group consisting of halogen, lower alkyl, aryl, and OR b wherein Rb is H, lower alkyl, or aryl; (d) aryl; and (e) lower alkyl; comprising the following steps: (1) subjecting a compound of formula (II) wherein R a is H, lower alkyl, alkenyl and alkynyl, and R c is: H; trifluoromethyl; phenyl, optionally substituted with fluoro, chloro, nitro, methoxy; or lower alkoxycarbonyl; to a diazo transfer reaction with a sulfonyl azide derivative to obtain a compound of formula (III) wherein R a being as defined above; (2) contacting the compound of formula (III) with a transition metal compound comprising Rh, Cu or Ru in presence of a hydroxy compound of formula ROH, R being as defined above, to obtain a compound of formula (IVa) wherein R and R a being as defined above; (3) contacting the compound of formula (IVa), wherein R and R a being as defined above, with an aromatization agent to obtain the compound of formula (I), wherein R being as defined above and X is the group wherein R a is H, lower alkyl, alkenyl and alkynyl; and when R a is hydrogen, oxidizing the compound of formula (I) so obtained to yield the compound of formula (I) wherein X is O.