Research Article
A Facile Stereoselective Total Synthesis of (R)-Rugulactone
Scheme 2
Reagents and conditions: (a) (i) DMSO, (COCl)2, Et3N, CH2Cl2, −78°C, 1 h. (ii) Triethyl phosphonoacetate, NaH, dry Benzene, 0°C-RT, 8 h, 95%. (b) LiAlH4, AlCl3, THF, 0°C,1 h, 82%. (c) (−)-DET, Ti(O-i-Pr)4, TBHP, dry CH2Cl2, molecular sieves 4 , −15°C, 87%. (d) Red-al, THF, −20°C, 6 h, 96%. (e) TBDMSCl, Et3N, DMAP, CH2Cl2, RT, 8 h, 96%. (f) Na, Liq. NH3, dry THF, −78°C, 15 min, 92%. (g) (i) DMSO, (COCl)2, Et3N, CH2Cl2, −78°C, 1 h. (ii) EtO2CCH2P(O)(OCH2CF3)2, NaH, dry THF, −78°C, 2 h, 74%. (h) CSA, MeOH:CH2Cl2 (1 : 1), RT, 85%. (i) DMSO, (COCl)2, Et3N, CH2Cl2, −78°C, 1 h. (ii) (C6H5)3PCH3I, n-BuLi, THF, 0°C, 82%. (j) PTSA, MeOH, 3 h, 91%.
