2-氯甲基-3-(2-甲氧基乙氧基)丙烯与过量的锂粉和催化量的萘(2.5%)在羰基化合物(E 1 = R 1 R 2 CO)存在下于THF中反应在-78至0℃下,在水解后,在0至20℃下添加环氧化物[E 2= R 3 R 4 C(O)CHR 5 ],得到预期的亚甲基二醇。这些二醇经过连续的硼氢化-氧化和进一步的氧化后,会发生自发环化,从而提供一系列不同取代的全氢呋喃[2,3- b ]吡喃。
Substituted perhydrofuropyrans: easy preparation from 2-chloromethyl-3-(2-methoxyethoxy)propene through 3-methylene-1,6-diols
摘要:
The reaction of 2-chloromethyl-3-(2-methoxyethoxy)prop-1-ene (1) with an excess of lithium powder and a catalytic amount of naphthalene (2.5%) in the presence of a carbonyl compound (E-1 =R-1 (RCO)-C-2) in THF at -78 to 0 degrees C, followed by treatment with an epoxide [E-2=(RRC)-R-3-C-4(O)CHR5] at 0 to 20 degrees C leads, after hydrolysis, to the expected unsaturated diols 2. When some compounds 2 (2e-h) are successively hydroborated (BH3 . THF) and oxidised (33% H2O2 and then PCC), the expected perhydrofuropyrans 3e-h are isolated directly. (C) 2000 Elsevier Science Ltd. All rights reserved.