{'fraction_non_alphanumeric': 0.03598971722365039, 'fraction_numerical': 0.012853470437017995, 'mean_word_length': 5.7155172413793105, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Direct catalytic asymmetric synthesis of highly functionalized tetronic acids/tetrahydro-isobenzofuran-1,5-diones via combination of cascade three-component reductive alkylations and Michael-aldol reactions.

A practical and sustainable chemical process for the synthesis of highly substituted tetrahydro-isobenzofuran-1,5-diones was achieved for the first time through asymmetric cascade Michael-aldol reaction of 4-hydroxy-3-alkyl-5H-furan-2-ones with alkyl vinyl ketones in the presence of a catalytic amount of l-proline or 9-amino-9-deoxyepiquinine/TCA. In this article, we discovered for the first time the asymmetric synthesis of privileged bicyclic lactones through kinetic resolution and show the synthetic application to pharmaceuticals and natural products synthesis.