Patent ID: 8148528

Claim:
A compound comprising of Formula 21a: wherein: R 1 and R 2 are independently chosen from hydrogen, OH, NH 2 , SH, CF 3 , hydrocarbyl, substituted hydrocarbyl, alkyl ketal, alkyl thiol ketal, and alkyl dithiol ketal, wherein when R 1 and R 2 are different they form an epimeric pair, and wherein R 1 and R 2 together may form a group chosen from =0, ═S, cycloalkyl ketal, cycloalkyl thiol ketal, and cycloalkyl dithiol ketal; R 3 is chosen from hydrogen, halogen, OH, NH 2 , CN, CF 3 , SO 2 R 8 , hydrocarbyl, and substituted hydrocarbyl; R 4 and R 5 are independently chosen from —(CH 2 ) n CH 3 and CH 3 ; R 8 is chosen from hydrocarbyl and substituted hydrocarbyl; X is halogen; Y is chosen from a benzyloxycarbonyl group, an alkylamidocarbonyl group, a trialkylsilyl group, an alkylsulfonyl group, and an aryl sulfonyl group; and n is an integer from 1 to 8.