2-氯甲基-3-(2-甲氧基乙氧基)丙-1-烯的行为是多用途的三亚甲基二价阴离子合成子,它是在羰基化合物存在下通过DTBB催化锂化获得的各种亚甲基二醇的前体(E 1 = R 1 R 2 CO)在-78至0°C下的THF中,然后加入环氧化物[E 2 = R 3 R 4 C(O)CHR 5在0至20℃下进行最终水解。这些二醇在碘和氧化银(I)的存在下于THF或二氧六环-水中进行双分子碘化醚化反应,生成相应的1,7-二氧杂螺[4.4]壬烷,可以很容易地氧化成各种1,7 -dioxaspiro [4.4] nonan-6-ones。这些骨骼存在于多种天然产物中。
2-氯甲基-3-(2-甲氧基乙氧基)丙-1-烯的行为是多用途的三亚甲基二价阴离子合成子,它是在羰基化合物存在下通过DTBB催化锂化获得的各种亚甲基二醇的前体(E 1 = R 1 R 2 CO)在-78至0°C下的THF中,然后加入环氧化物[E 2 = R 3 R 4 C(O)CHR 5在0至20℃下进行最终水解。这些二醇在碘和氧化银(I)的存在下于THF或二氧六环-水中进行双分子碘化醚化反应,生成相应的1,7-二氧杂螺[4.4]壬烷,可以很容易地氧化成各种1,7 -dioxaspiro [4.4] nonan-6-ones。这些骨骼存在于多种天然产物中。
powder and a catalytic amount of naphthalene (2.5%) in the presence of a carbonyl compound (E1=R1R2CO) in THF at −78 to 0°C, followed by the addition of an epoxide [E2=R3R4C(O)CHR5] at 0 to 20°C leads, after hydrolysis, to the expected methylidenic diols. These diols when subjected to successive hydroboration–oxidation and further oxidation, spontaneous cyclization occurs to furnish a series of differently
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
作者:Emilio Lorenzo、Francisco Alonso、Miguel Yus
DOI:10.1016/s0040-4039(00)00009-5
日期:2000.3
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.
Straightforward synthesis of 1,7-dioxaspiro[4.4]nonanes
作者:Francisco Alonso、Jaisiel Meléndez、Miguel Yus
DOI:10.1016/j.tetlet.2003.12.094
日期:2004.2
The reaction of 2-chloromethyl-3-(2-methoxyethoxy)prop- I -ene with an excess of lithium powder and a catalytic amount of naphthalene (2.5%) in the presence of a carbonyl compound (E-1 = (RRCO)-R-1-C-2) in THF at -78 to 0degreesC, followed by the addition of an epoxide [E-2 = (RR4)-R-3 C(O)CHR5] at 0 to 20degreesC leads, after hydrolysis, to the expected methylidenic diols. These diols, in the presence of iodine and silver(l) oxide in dioxane-water, undergo double intramolecular iodoetherification to give the corresponding 1,7-dioxaspiro[4.4]nonanes, which in addition can be easily oxidised to a variety of 1,7-dioxaspiro[4.4]nonan-6-ones. (C) 2003 Elsevier Ltd. All rights reserved.