Introduction of a Hydroxylmethyl Group Onto the Ring of 4-Cyclopentene-1,3-diol Monoacetate

Reaction of 4-cyclopentene-1,3-diol monoacetate and ClMgCH2SiMe2(i-PrO) (2a) with CuI as a catalyst afforded the 1,4-isomer 3a, while reaction with the reagent derived from 2a and CuCN in a ratio of 1:1 produced the 1,2-isomer 4a. These products were transformed into useful intermediates through Tamao oxidation of the CH2SiMe2(i-PrO) group into the CH2OH group.