To explore the possibilities of a near-term intermediate-scale quantum algorithm and long-term fault-tolerant quantum computing, a fast and versatile quantum circuit simulator is needed. Here, we introduce Qulacs, a fast simulator for quantum circuits intended for research purpose. We show the main concepts of Qulacs, explain how to use its features via examples, describe numerical techniques to speed-up simulation, and demonstrate its performance with numerical benchmarks.

The asymmetric total syntheses of tirandamycins A-D and tirandalydigin as well as the synthesis of the left-hand fragment of streptolydiginone and streptolydigin from a common intermediate are described. The comprehensive approach features the highly enantio- and diastereoselective assembly of the anti,anti,syn-stereotetrad unit which relies on a cinchona alkaloid-catalyzed asymmetric Morita-Baylis-Hillman reaction.

An effective method for the protection of carboxylic acids with a triisopropylsiloxymethyl (TIPSOCH(2)) group is described. The reactions of various carboxylic acids with C(12)H(25)SCH(2)OTIPS in the presence of CuBr(2), Et(3)N, and molecular sieves 4A afford the corresponding triisopropylsiloxymethyl esters in good yields.

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A method for the enantio‐ and diastereoselective construction of all possible stereoisomers of a polypropionate stereotetrad having four contiguous stereogenic centers has been developed. The approach features an iterative sequence of cinchona‐alkaloid‐catalyzed Morita–Baylis–Hillman reaction and subsequent diastereoselective hydrogenation. By this method, benzaldehyde was successfully converted into eight diastereoisomeric 3,5‐dihydroxy‐2,4‐dimethyl‐5‐phenylpentanoic acid ester derivatives with high enantiomeric purities (99 % ee) in 25–67 % overall yield (eight steps) in a reagent‐controlled manner.