C in THF at 0" C and then warmed to 20" C for 1 h (entry 2, Table 2) we isolated a 57: 43 mixture of propargylic alcohol 3a and diol 7 (Scheme 2). When 1 and nBuLi were reacted for only 30 min at-20" C or-78" C (entries 3 and 4, Table 2) we isolated a mixture of the expected product 3a and 6, resulting from addition of nBuLi to the electrophile in 4258 and 60: 40 ratios (see Table 21, respectively. By adjusting the molar ratio of the reagents from ...
