Reagents and conditions: i, Ph3CCl, Et3N, CH2Cl2, 92%; ii, LiCMCCH2OTBS (3), THF, BF3?OEt2, 278 uC, 93%; iii, TBSCl, imidazole, DMF; iv, TBAF, THF, 80% from 2; v, Red-Al, Et2O; vi, MsCl, LiCl, collidine, DMF, 0 uC A rt, 83% from 4; vii, LiSnBu3, THF, 278 uC, 93%; viii, TBAF, THF, 79%; ix, Tf2O, collidine, CH2Cl2, Et3N, 288 uC, 99%.

Reagents and conditions: i, BH3?SMe2, NaBH4 (cat), THF, 88%;ii, Ph3CCl, Et3N, CH2Cl2, 64%; iii, TBSCl, imidazole, DMF, 92%; iv,DIBALH, CH2Cl2, 0 uC, 94%; v, TPAP (cat), NMO, 4 A mol. sieves,CH2Cl2, 78%; vi, (CF3CH2O)2P(O)CH2CO2Me (11), KHMDS, 18-crown-6, THF, 89%; vii, DIBALH, CH2Cl2, 0 uC, 76%; viii, MsCl, LiCl, collidine,DMF, 0 uC A rt, 99%; ix, LiSnBu3, THF, 278 uC, 93%; x, TBAF, THF,collidine, 0 uC A rt, 63%; xi, Tf2O, collidine, CH2Cl2, Et3N, 278 uC, 91%.

Reagents and conditions: i, LiAlH4, THF; Bu3SnOTf, 0 uC A rt, 83%; ii, 5, PdCl2(MeCN)2, NMP; iii, MsCl, LiCl, collidine, DMF, 0 uC A rt; iv, LiSnBu3, THF, 278 uC, 78% from 15; v, TBAF, THF, Et3N, 72%; vi, Tf2O, collidine, CH2Cl2, Et3N, 278 uC, 99%.