141923-60-6Relevant articles and documents
A deprotection procedure using SO3H silica gel to remove non-silyl protecting groups
Karaki, Fumika,Kuwada, Miki,Tajiri, Saki,Kanda, Misaki,Yanai, Mari,Kamimura, Mitsuhiro,Itoh, Kennosuke,Fujii, Hideaki
, p. 212 - 220 (2019/05/06)
Protecting groups are indispensable in organic synthesis and there is a great need for a variety of deprotection methods. Here, we investigated the scope of the application of a deprotection procedure using SO3H silica gel, which we have previously reported as a desilylation procedure. Under these conditions, -OMOM, -OSEM, -OTHP, and -OAc groups and dimethyl acetal were cleaved. Pivaloyloxy, benzyloxy and methoxy carbonyl groups remained intact and selective deprotection of TBS groups in the presence of other protecting groups was accomplished. We succeeded in cleaving an acetyl group on a secondary alcohol in a highly polar nortropine derivative. Our findings here provide another deprotection option and would be helpful in the synthesis of multifunctional compounds.
Mild and practical acylation of alcohols with esters or acetic anhydride under distannoxane catalysis
Orita, Akihiro,Sakamoto, Katsumasa,Hamada, Yuji,Mitsutome, Akihiro,Otera, Junzo
, p. 2899 - 2910 (2007/10/03)
Distannoxane catalysts effect acylation of alcohols by action of esters and acetic anhydride. In particular, use of enol esters provides an extremely useful method. Primary alcohols are acylated in preference to secondary ones as well as phenol. Both acid- and base-sensitive functional groups remain intact. Especially unique is the discrimination of thio function which is completely tolerant under the present reaction conditions. This method is highly practical since operation is quite simple. Esters and solvents can be used without purification and no inert atmosphere is necessary. The products can be isolated simply by column chromatography or distillation without aqueous workup.
Selective pivaloylation of hydroxyl groups by 3-Pivaloyl-1,3-thiazolidine-2-thione under neutral conditions
Yamada, Shinji
, p. 2171 - 2174 (2007/10/02)
Under neutral conditions, 3-pivaloyl-l,3-thiazolidine-2-thione (PTT) was found to act as a selective pivaloylating reagent for hydroxyl groups. The primary hydroxyl groups of diols containing primary and secondary hydroxyl groups, and the phenolic hydroxyl groups of the diols having alcoholic and phenolic hydroxyl groups were selectively pivaloylated by PTT.