HIGHLY EFFECTIVE AND PRACTICAL STEREOSELECTIVE SYNTHESIS OF NEW HOMOALLYLIC ALCOHOLS WITH (-CAMPHOR AND (-)-FENCHONE SKELETON())

The new chiral nonracemic homoallylic exo-alcohols 6, 7, 10 with (1R)( +)-camphor (1) and endo-alcohols 8, 9, 11 with (1R)-(-)-fenchone (2) s keleton were synthesized in high yields by the stereoselective additio n of allyl and substituted allylic Grignard reagents 3-5 to 1 and 2, r espectively. The addition of the 2-butenyl (crotyl) reagent 5 occurred with high selectivity leading exclusively to alpha-methylallyl alcoho l 10 with ketone 1 and to (Z)-2-butenyl alcohol 11 with ketone 2. The absolute configurations of the homoallylic alcohols 6-11 were determin ed by NMR methods.