The roadmap for sucrose - a very inexpensive raw product.

Sucrose, an inexpensive starting material available in virtually unlimited quantities, affords entry into a variety of novel and useful carbohydrate compounds. Selective protection of the secondary hydroxyl groups gives rise to a group of O-benzyl-protected intermediates that are useful in the synthesis of chiral phosphines and amino compounds of interest in the study of biological systems. The benzyl-protected fine chemicals are also key components in the synthesis of crown, thia-crown, and aza-crown compounds.

Machine Learning Algorithm Guides Catalyst Choices for Magnesium-Catalyzed Asymmetric Reactions.

Organic-chemical literature encompasses large numbers of catalysts and reactions they can effect. Many of these examples are published merely to document the catalysts' scope but do not necessarily guarantee that a given catalyst is "optimal"-in terms of yield or enantiomeric excess-for a particular reaction. This paper describes a Machine Learning model that aims to improve such catalyst-reaction assignments based on the carefully curated literature data.

Selective transformations of friedelanes isolated from cork smoker wash solids.

Friedelin (1) and 3-acetoxyfriedel-3-en-2-one (4), commonly known as friedelane triterpenoids, have been isolated from cork smoker wash solids (also known as black wax) on a multi-gram scale. These compounds are valuable starting materials for the synthesis of new friedelane derivatives. Stereoselective reduction of friedelin by treatment with LiAlH, sodium, or catalytic hydrogenation results in the formation of both isomers of friedelinol (5 and 7) in excellent yields.

Effect of modification of betulinic acid at the C3-carbon atom of homolupane triterpenoids on the antiproliferative activity in vitro.

In search of new cytotoxic derivatives based on the lupane scaffold, methyl betulonate and methyl 20,29-dihydrobetulonate were conjugated with Reformatsky reagents to provide homolupanes extended at the C3-carbon atom. Further transformations of the functional groups afforded a series of derivatives with 2-hydroxyethyl and allyl alcohol moieties. Their varying antiproliferative activity in vitro was then investigated in four cancer cell lines and in normal human BJ fibroblasts.

Oxidative Functionalization of Trinor-18α-olean-17(22)-ene Derivatives. Annulation of the E-Ring by an Intramolecular Aldol Reaction.

-Dihydroxylation of trinor-18α-olean-17(22)-ene with osmium tetroxide led to diol . Its cleavage with lead tetraacetate gave tetracyclic ketoaldehyde . By comparison, the ozonation of trinor-18α-olean-17(22)-ene in the presence of -toluenesulfonic acid gave the corresponding ketoacetal .