Tin(II) chloride dihydrate: A mild and efficient reagent for cleaving acetals.
摘要:
Tin(II) chloride dihydrate (SnCl2.2H2O) efficiently converts conjugated dioxolanes, and both dimethoxy and diethoxy acetals to aldehydes (84-98%). Similarly, nonconjugated dimethoxy and diethoxy acetals are also efficiently converted to aldehydes (84-94%). Conjugated pyrans and nonconjugated dioxolanes, however, are only converted to aldehydes in 17-38% yields.
Novel method for transforming aldehydes and acetals into 1,3-dithianes has been achieved with the aid of organotin thioalkoxides and organotin triflates. Under these reaction conditions, various acid-sensitive groups are tolerated. Differentiation between aromatic or aliphatic aldehydes and acetals has been realized.
Acetals are obtained in good to excellent yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of a catalytic amount of lithium tetrafluoroborate. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates.
The title β-alkylation is achieved through a sequence of sulfenylation of α-enal acetals, -BuLi-promoted alkylation, and oxidative hydrolysis.
标题β-烷基化是通过一系列α-烯醇缩醛的亚磺酰基化,-BuLi促进的烷基化和氧化水解来实现的。
Diastereoselective Prins-Type Reaction of Cycloalkenylcyclopropanol Silyl Ethers and α,β-Unsaturated Aldehyde Acetals
作者:Ivan L. Lysenko、Heong-Sub Oh、Jin Kun Cha
DOI:10.1021/jo071272o
日期:2007.10.1
Electrophilic addition of 1-(1-cyclohexenyl)-1-cyclopropanol trimethylsilylether to α,β-unsaturated aldehyde acetals under Lewisacidic conditions proceeds with good to excellent diastereoselectivity to afford spirocyclobutanones containing three contiguous stereocenters. A convenient entry to enantioselective syntheses is available by use of a nonracemic C2-symmetric acetal. Elaboration of the resulting
BITTER TASTE MODIFIERS INCLUDING SUBSTITUTED 1-BENZYL-3-(1-(ISOXAZOL-4-YLMETHYL)-1H-PYRAZOL-4-YL)IMIDAZOLIDINE-2,4-DIONES AND COMPOSITIONS THEREOF
申请人:SENOMYX, INC.
公开号:US20160376263A1
公开(公告)日:2016-12-29
The present invention includes compounds and compositions known to modify the perception of bitter taste, and combinations of said compositions and compounds with additional compositions, compounds, and products. Exemplary compositions comprise one or more of the following: cooling agents; inactive drug ingredients; active pharmaceutical ingredients; food additives or foodstuffs; flavorants, or flavor enhancers; food or beverage products; bitter compounds; sweeteners; bitterants; sour flavorants; salty flavorants; umami flavorants; plant or animal products; compounds known to be used in pet care products; compounds known to be used in personal care products; compounds known to be used in home products; pharmaceutical preparations; topical preparations; cannabis-derived or cannabis-related products; compounds known to be used in oral care products; beverages; scents, perfumes, or odorants; compounds known to be used in consumer products; silicone compounds; abrasives; surfactants; warming agents; smoking articles; fats, oils, or emulsions; and/or probiotic bacteria or supplements.