In this study, the enantioselective oxylactonization of ortho‐alk‐1‐enylbenzoates with chiral hypervalent iodine(III) reagents yielded 3‐alkyl‐4‐hydroxyisochroman‐1‐ones with high enantiomeric purity (ca. 90 % ee). The enantioselective oxidation was also performed under catalytic conditions, in which a catalytic amount (10 mol‐%) of a chiral iodoarene was oxidized to the hypervalent iodine species in situ using a stoichiometric co‐oxidant, m‐chloroperbenzoic acid (mCPBA). The catalytic oxidation mediated by chiral hypervalent iodine(III) species yielded enantiocontrolled syn products, while the direct oxidation of the substrate with mCPBA occurred as background oxidation to give racemic anti products. Under optimized conditions, the catalytic oxylactonization led to high levels of enantioselectivity (ca. 90 % ee) and improved syn/anti selectivities (ca. 80 % syn). The product distribution indicated that the lactate side‐chain on the chiral iodoarene precatalyst plays an important role in enhancing both the enantioselectivity and the catalytic efficiency in the oxylactonization.

Stereoselective oxylactonization of ortho-alkenylbenzoate with chiral hypervalent iodine is applied to the asymmetric synthesis of 4-oxyisochroman-1-one polyketide metabolites including 4-hydroxymellein (1), a derivative of fusarentin 2, monocerin (3), and an epimer of monocerin epi-3.

Ketone-based brominating agents (KBA), orthosubstituted 2,2,2-tribromoacetophenones, have been developed, and the highly enantioselective and practical α-bromination of aldehydes with KBA was achieved. The reaction could be performed in the presence of only 0.1−1 mol % of catalyst without using a halogenated solvent at 0 °C and was found to be scalable.

The first total syntheses of (12R)-and (12S)-12-hydroxymonocerins are described. The oxolane-fused isochroman-1-one framework is stereoselectively constructed via a double oxy-cyclization using a lactatebased chiral hypervalent iodine reagent. A catalytic variant of the double oxy-cyclization is also demonstrated using a chiral iodoarene as the precatalyst and m-CPBA as the co-oxidant.

The enantioselective oxyarylation of (E)-6-aryl-1-silyloxylhex-3-ene was achieved using a lactate-based chiral hypervalent iodine(III) reagent in the presence of boron trifluoride diethyl etherate. The silyl ether promotes the oxidative cyclization, and enhances the enantioselectivity. In addition, the corresponding aminoarylation was achieved.